Toilet body

ABSTRACT

A toilet body includes a toilet bowl part which has a bowl-shaped waste receiving surface and a water reservoir part, and a first water discharge part, in which the waste receiving surface has a shelf surface for guiding the flush water discharged from the water discharge hole into one side of the toilet bowl part in a circumferential direction, the shelf surface is structured so that a shape in a surface cut along a radial direction of the toilet bowl part is a flat surface, and a slope in the radial direction of the shelf surface in the rear region is set to be larger than a slope in the radial direction of the shelf surface in a lateral region of the waste receiving surface located on either the left or right side of the water reservoir part.

FIELD OF THE INVENTION

The present invention relates to a toilet body.

BACKGROUND OF THE INVENTION Description of the Related Art

Conventionally, various studies have been made on a cleaning method for discharging waste. JP 2016-89431 A discloses a flush toilet which can generate a swirling flow on one region out of left and right regions of a toilet bowl part toward a rear thereof, and generate an induction flow for pushing waste into an inlet of a toilet drain channel by introducing a portion of the swirling flow from the rear into a water reservoir part of the toilet bowl part.

SUMMARY OF THE INVENTION

A case of generating the induction flow for pushing waste into the inlet of the toilet drain channel by introducing flush water from the rear into the water reservoir part of the toilet bowl part is considered. In this case, it is preferable to be able to increase an amount of flush water flowing from the rear into the water reservoir part in order to obtain good waste discharge capability. The inventors have obtained the knowledge that there is a new measure to improve the waste discharge capability based on such a point of view.

An aspect of the present invention is made in view of such a problem, and one of the objects of the present invention is to provide a technology of improving waste discharge capability in order to discharge waste using a water flow introduced from the rear into a water reservoir part.

A first aspect of the present invention for solving the above-mentioned problems is a toilet body. A toilet body according to a first aspect includes a toilet bowl part which has a bowl-shaped waste receiving surface and a water reservoir part recessed downward from a lower end edge of the waste receiving surface, a drainage part which is connected to a bottom part of the toilet bowl part, and a first water discharge part which discharges flush water from a first water discharge hole toward one side in a circumferential direction into the toilet bowl part to form a water flow which travels along a rear region of the waste receiving surface located behind the water reservoir part toward one side in a circumferential direction, in which the water reservoir part is structured to form an induction flow which pushes waste into the toilet drain channel by introducing a water flow from the rear of the toilet bowl part into the water reservoir part while contacting upright wall surfaces provided on one side out of left and right sides of the water reservoir part, the waste receiving surface has a shelf surface for guiding flush water discharged from the water discharge hole toward one side in the circumferential direction, the shelf surface is structured so that a shape in a surface cut along a radial direction of the toilet bowl part is a flat surface, and a slope in the radial direction of the shelf surface in the rear region is set to be larger than a slope in the radial direction of the shelf surface in a lateral region of the waste receiving surface located on either the left or right side of the water reservoir part.

According to the first aspect, compared to the case where the slope of the shelf surface in the rear region is equal to or less than the slope of the shelf surface in the lateral region, a portion of the flush water which travels circumferentially across the shelf surface of the rear region appropriately and easily drops into the water reservoir part. As a result, the amount of flush water flowing from the rear of the toilet bowl part into the water reservoir part can be increased, and the waste discharge capability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a toilet body according to a first embodiment;

FIG. 2 is a plan view showing the toilet body according to the first embodiment;

FIG. 3 is a side cross-sectional view showing the toilet body according to the first embodiment;

FIG. 4 is a cross-sectional view taken along the line A-A in FIG. 3;

FIG. 5 is a diagram showing a portion of a cross section taken along the line B-B in FIG. 2;

FIG. 6 is a diagram mainly showing a portion of a cross section taken along the line C-C in FIG. 5;

FIG. 7 is an exploded perspective view of the toilet body according to the first embodiment;

FIG. 8 is a cross-sectional view taken along the line D-D in FIG. 3;

FIG. 9 is a diagram showing a portion of a cross section taken along the line E-E in FIG. 5;

FIG. 10 is another plan view showing the toilet body according to the first embodiment;

FIG. 11 is still another plan view showing the toilet body according to the first embodiment;

FIG. 12 is an enlarged view of a portion of FIG. 3.

FIG. 13 is a diagram mainly showing a portion of a cross section taken along the line B-B in FIG. 2;

FIG. 14 is a diagram showing flows of flush water in a first stage;

FIG. 15 is a diagram showing flows of flush water in a second stage;

FIG. 16 is another diagram showing the flows of flush water in the second stage;

FIG. 17 is a graph showing a slope of a shelf surface according to the first embodiment;

FIG. 18 is a graph showing a radius of curvature of a connecting surface according to the first embodiment;

FIG. 19 is an enlarged view of a portion of FIG. 4; and

FIG. 20A is a cross-sectional view taken along the line F-F in FIG. 3, FIG. 20B is a cross-sectional view taken along the line G-G in FIG. 3, and FIG. 20C is a cross-sectional view taken along the line H-H in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

In the following embodiment and modifications, same reference characters denote same constituting elements, and the repetitive description will be omitted. In each drawing, part of the constituting elements may be appropriately omitted, or the size of a constituting element may be appropriately enlarged or reduced, for the sake of convenience. The drawings should be viewed according to directions of reference characters. Unless otherwise specified, the term “contact” in the present specification also includes a case where two components referred are in indirect contact with each other as well as a case where two components are in direct contact with each other via another member.

First Embodiment

First, a first point of a flush toilet 10 according to a first embodiment 1 will be described. FIG. 1 is a perspective view of a toilet body 12 used in the flush toilet 10 according to the first embodiment. FIG. 2 is a plan view of the toilet body 12. FIG. 3 is a side cross-sectional view of the toilet body 12. FIG. 4 is a cross-sectional view taken along the line A-A in FIG. 3.

The flush toilet 10 includes the toilet body 12 and a flush water supply device 14. As shown in FIG. 4, the flush water supply device 14 according to the present embodiment is structured to use a water storage tank (not shown), a distributor 16, and the like.

The toilet body 12 according to the present embodiment is made of a ceramic material, but may be made of a material such as a resin. The toilet body 12 according to the present embodiment is a Western-style toilet. The toilet body 12 according to the present embodiment is a floor mounted type in which a toilet body is provided on a floor surface Fs (see FIG. 3) of a toilet room.

Hereinafter, a positional relationship between components of the flush toilet 10 will be described using three directions orthogonal to one another. This direction is a front-rear direction X, a left-right direction Y, and a top-bottom direction Z of the toilet body 12. The front-rear direction X and the left-right direction Y are a horizontal direction, and correspond to front, rear, left, and right sides of a seated person sitting on a toilet seat (not shown) attached to the toilet body 12 in a normal posture. The top-bottom direction Z is a perpendicular direction.

In addition, in the present specification, the positional relationship between the components of the flush toilet 10 will be described using a circumferential direction and a radial direction of a toilet bowl part 18 of the toilet body 12. Here, the “circumferential direction” refers to a direction turning around a center Cp (see FIG. 2) of an upper end inner edge part 18 a of the toilet bowl part 18 when the toilet body 12 is viewed from above. In addition, the “radial direction” refers to a direction orthogonal to a perpendicular line passing through the center Cp.

Refer to FIGS. 2 and 3. The toilet body 12 has the toilet bowl part 18. The upper end inner edge part 18 a of the toilet bowl part 18 is continued to an upper surface part 20 of the toilet body 12, and a rear part of the upper surface part 20 is provided with a mounting hole 22 for attaching a toilet seat.

The toilet bowl part 18 includes a bowl-shaped waste receiving surface 24 for receiving waste and a water reservoir part 26 recessed downward from a lower end edge of the waste receiving surface 24. The waste receiving surface 24 is shaped so that a radius of curvature in plan view is minimal at a front end part 24 a.

The toilet bowl part 18 has a left side portion 18 b (first side portion) on a left side (right side on a page in FIG. 2) which is one of left and right sides and a right side portion 18 c (second lateral region) which is the other (left side on a page in FIG. 2) of the left and right sides. The left side portion 18 b is a portion of the toilet bowl part 18 disposed on one of the left and right sides with respect to a left-right center line Lc of the toilet bowl part 18, and the right side portion 18 c is a portion of the toilet bowl part 18 disposed on the other of the left and right sides with respect to the left-right center line Lc. In plan view, the left-right center line Lc is a straight line which bisects a dimension along a left-right direction Y of an inner surface portion of the toilet bowl part 18 and extends along the front-rear direction X.

As shown in FIG. 4, the toilet body 12 includes water discharge parts 28A and 28B for discharging flush water into the toilet bowl part 18. As the water discharge parts 28A and 28B, a first water discharge part 28A having a first water discharge hole 30A provided on the right side portion 18 c of the toilet bowl part 18 and a second water discharge part 28B having a second water discharge hole 30B provided on the left side portion 18 b of the toilet bowl part 18. The first water discharge hole 30A or the second water discharge hole 30B according to the present embodiment is formed behind the water reservoir part 26 and at the rear part of the toilet bowl part 18. The first water discharge hole 30A according to the present embodiment is formed on the right side which is one of the left and right sides of the water reservoir part 26, and the second water discharge hole 30B according to the present embodiment is formed on the left side which is the other of the left and right sides of the water reservoir part 26.

The first water discharge hole 30A is opened toward the front, and discharges flush water to one side (counterclockwise direction on a page in FIG. 9, hereinafter, simply referred to as a counterclockwise direction) of the toilet bowl part 18 in a circumferential direction. The second water discharge hole 30B is opened toward the right which is the other of the left and right sides, and discharges flush water in the counterclockwise direction into the toilet bowl part 18.

The first water discharge part 28A has a first water passage 32A for supplying flush water to the first water discharge hole 30A. The second water discharge part 28B has a second water passage 32B for supplying flush water to the second water discharge hole 30B. The first water passage 32A is provided on the right side portion of the toilet body 12, and the second water passage 32B is provided on the left side portion of the toilet body 12. The flush water is supplied from the flush water supply device 14 to the first water passage 32A and the second water passage 32B.

FIG. 5 is a diagram showing a portion of a cross section taken along the line B-B in FIG. 2. FIG. 6 is a diagram mainly showing a portion of a cross section taken along the line C-C in FIG. 5. The toilet bowl part 18 has a hanging wall part 34 hanging from the upper end inner edge part 18 a of the toilet bowl part 18. An inner peripheral surface of the hanging wall part 34 is continued downward from the upper end inner edge part 18 a of the toilet bowl part 18 to an outer peripheral end part 24 b of the waste receiving surface 24. The inner peripheral surface of the hanging wall part 34 is not provided with a horizontal plane in a range from the upper end inner edge part 18 a of the toilet bowl part 18 to the outer peripheral end part 24 b of the waste receiving surface 24. As a result, the inner peripheral surface of the hanging wall part 34 is more easily wiped than the case where the inner peripheral surface of the hanging wall part 34 is provided with the horizontal plane.

In the present embodiment, the inner peripheral surface of the hanging wall part 34 is formed to extend radially inward as it goes downward from the upper end inner edge part 18 a. In addition to this, the inner peripheral surface of the hanging wall part 34 may be formed in an overhang shape in which the hanging wall part 34 extends radially outward as it goes downward from the upper end inner edge part 18 a.

As shown in FIG. 1, the hanging wall part 34 according to the present embodiment is provided in a range over an entire circumference of the toilet bowl part 18. The inner peripheral surface of the hanging wall part 34 according to the present embodiment smoothly extend at locations other than the water discharge holes 30A and 30B in the range over substantially the entire circumference. The hanging wall part 34 may be provided at least in a range of a half or more of the circumferential direction in the range over the entire circumference of the circumferential direction of the toilet bowl part 18. In addition to this, the hanging wall part 34 may be at least provided in a range of a major portion of the circumferential direction in a range over the entire circumference of the circumferential direction of the toilet bowl part 18. Here, the major portion is called, for example, a range of 80% or more of the range over the entire circumference in the circumferential direction of the toilet bowl part 18.

Hereinafter, since the first water discharge part 28A and the second water discharge part 28B have many configurations in common, the common configurations will be described with reference to the drawings showing the first water discharge part 28A. Refer to FIGS. 5 and 6. The first water discharge hole 30A of the first water discharge part 28A penetrates the hanging wall part 34. An inner lower surface 30 a of the first water discharge hole 30A smoothly connects between an inner lower surface 32 a of the first water passage 32A and the waste receiving surface 24 as the inner surface of the toilet bowl part 18. In the present specification, “smoothly” refers to a state in which the surface referred is smooth without having ruggedness or steps. An inner upper surface 30 b of the first water discharge hole 30A is provided under an inner upper surface 32 b of the first water passage 32A.

The hanging wall part 34 forms the first water discharge hole 30A and has a first hole forming part 36A which is provided above the first water discharge hole 30A. An inner peripheral surface of the first hole forming part 36A is smoothly connected in the range from the upper end inner edge part 18 a of the toilet bowl part 18 to the first water discharge hole 30A. The inner peripheral surface of the first hole forming part 36A is smoothly connected to the inner peripheral surface of the other portion of the hanging wall part 34 adjacent to both sides of the first hole forming part 36A in the circumferential direction.

As a result, the inner peripheral surface of the first hole forming part 36A of the hanging wall part 34 forming the first water discharge hole 30A is provided at a location where it is smoothly connected to the upper end inner edge part 18 a of the toilet bowl part 18. Therefore, the inner peripheral surface of the first hole forming part 36A of the hanging wall part 34 together with the upper end inner edge part 18 a of the toilet bowl part 18 is more easily wiped than the case where the wall part forming the first water discharge hole 30A is disposed at a location recessed from the upper end inner edge part 18 a of the toilet bowl part 18, and thus good cleaning performance can be obtained.

In addition, a size of the first water discharge hole 30A is smaller than the case where the upper end inner edge part 18 a of the toilet bowl part 18 forms the first water discharge hole 30A, and thus good design property can be obtained. In addition, as compared with the case where the upper end inner edge part 18 a of the toilet bowl part 18 forms the first water discharge hole 30A, the situation where the flush water discharged from the first water discharge hole 30A travels to the upper end inner edge part 18 a, so the flush water travels to the upper surface part 20 of the toilet body 12 is easily avoided. In addition, as compared with the case where the upper end inner edge part 18 a of the toilet bowl part 18 forms the first water discharge hole 30A, a height of the flush water flowing in the toilet bowl part 18 is suppressed, and the situation where splash of the flush water is scattered to the outside of the toilet bowl part 18 is easily avoided.

From the viewpoint of obtaining the above effects, it is preferable to satisfy the following conditions. A height Ha of the first hole forming part 36A of the hanging wall part 34 is defined as a height from the upper end of the upper end inner edge part 18 a of the toilet bowl part 18 to the inner upper surface 30 b of the first water discharge hole 30A. In addition, the height from the upper end of the upper end inner edge part 18 a of the toilet bowl part 18 to the inner lower surface 30 a of the first water discharge hole 30A is referred to as Hb. At this time, the height Ha of the first hole forming part 36A of the hanging wall part 34 is preferably set to be a size equal to or larger than half the height Hb. This condition is derived based on an experimental study by the inventors. As a result, the inner peripheral surface of the first hole forming part 36A of the hanging wall part 34 has an appropriate size for wiping and cleaning, so the inner peripheral surface thereof can be wiped more easily and better cleaning performance can be obtained.

In addition, the size of the first water discharge hole 30A is reduced, and better design property can be obtained. In addition, it becomes difficult to make the flush water discharged from the first water discharge hole 30A travel to the upper end inner edge part 18 a, and it is easier to avoid the situation where the flush water travels to the upper surface part 20 of the toilet body 12. In addition, the height of the flush water flowing in the toilet bowl part 18 can be further suppressed, and the situation where the splash of flush water is scattered to the outside of the toilet bowl part 18 can be more easily avoided.

In addition, the inner lower surface 30 a of the first water discharge hole 30A smoothly connects between the inner lower surface 32 a of the first water passage 32A and the waste receiving surface 24 as the inner surface of the toilet bowl part 18. Therefore, the water in the first water passage 32A can easily flow into the toilet bowl part 18 along the inner lower surface 30 a of the first water discharge hole 30A without stopping in the first water passage 32A, and good sanitation can be achieved.

Although the first water discharge part 28A has been described in detail so far, the second water discharge part 28B is common in many respects. That is, the second water discharge hole 30B of the second water discharge part 28B also penetrates the hanging wall part 34. Although not shown, the inner lower surface of the second water discharge hole 30B also smoothly connects between the inner lower surface of the second water passage 32B and the waste receiving surface 24 of the toilet bowl part 18. The hanging wall part 34 forms the second water discharge hole 30B and has a second hole forming part 36B which is provided above the second water discharge hole 30B. The second hole forming part 36B has the same configuration as the first hole forming part 36A, and therefore the description thereof will be omitted.

Next, other features of the flush toilet 10 will be described. FIG. 7 is an exploded perspective view of the toilet body 12. As shown in FIGS. 1, 5, and 7, the toilet body 12 according to the present embodiment is constituted by joining between upper surface side portions 38A and 38B and a toilet bowl side portion 40 under the upper surface side portions 38A and 38B. The upper surface side portions 38A and 38B and the toilet bowl side portion 40 are joined by adhesion or the like. The upper surface side portions 38A and 38B and the toilet bowl side portion 40 are semi-finished products of the toilet body 12 necessary to obtain the toilet body 12 made of pottery, and are cast molded products obtained by cast molding. The toilet body 12 according to the present embodiment is constituted by joining between the upper surface side portions 38A and 38B and the toilet bowl side portion 40 as the cast molded products in an unfired state and then baking them.

The upper surface side portions 38A and 38B and the toilet bowl side portion 40 have a shape in which the toilet body 12 is divided. The upper surface side portions 38A and 38B are portions including at least a portion of the upper surface part 20 of the toilet body 12. The upper surface side portions 38A and 38B according to the present embodiment include a first upper surface side portion 38A corresponding to the first water discharge part 28A and a second upper surface side portion 38B corresponding to the second water discharge part 28B. The toilet bowl side portion 40 is a portion under the upper surface side portions 38A and 38B of the toilet body 12 and is a portion including a major portion of the toilet bowl part 18. Hereinafter, since the first upper surface side portion 38A and the second upper surface side portion 38B have many configurations in common, the common configurations will be described with reference to the drawings showing the first upper surface side portion 38A.

FIG. 8 is a cross-sectional view taken along the line D-D in FIG. 3. As shown in FIGS. 5 and 8, a boundary position between the upper surface side portions 38A and 38B and the toilet bowl side portion 40 is set at a position where a wall part forming the water discharge parts 28A and 28B corresponding to the upper surface side portions 38A and 38B are divided up and down. In FIG. 5 and the like, for convenience of explanation, the boundary position between the upper surface side portions 38A and 38B and the toilet bowl side portion 40 is indicated by a two-dot chain line, but these may not appear in the appearance. The locations where the water discharge holes 30A and 30B or the water passages 32A and 32B of the toilet bowl side portion 40 have a shape opened upward. The upper surface side portions 38A and 38B are disposed so as to close the locations where the water discharge holes 30A and 30B or the water passages 32A and 32B of the toilet bowl side portion 40 are formed from the upper side thereof.

As shown in FIGS. 5, 7, and 8, the first upper surface side portion 38A has a first upper wall part 42A constituting the inner upper surface 32 b of the first water passage 32A and a first hanging side wall part 44A at least constituting the first hole forming part 36A of the hanging wall part 34. The first upper wall part 42A constitutes a portion of the upper surface part 20 of the toilet body 12. The first hanging side wall part 44A constitutes the inner upper surface 30 b of the first water discharge hole 30A. Both side parts 44 a of the first hanging side wall part 44A constitute the other portion of the hanging wall part 34 adjacent to both sides of the first hole forming part 36A in the circumferential direction.

The toilet bowl side portion 40 has a pair of first side wall parts 46A constituting an inner side surface 32 c of the first water passage 32A and a first lower wall part 48A constituting the inner lower surface 32 a of the first water passage 32A. A pair of first side wall parts 46A have an entrance side opening part 50 which forms the first water discharge hole 30A. The first lower wall part 48A also constitutes the inner lower surface 30 a of the first water discharge hole 30A.

FIG. 9 is a diagram showing a portion of a cross section taken along the line E-E in FIG. 5. As shown in FIGS. 7 to 9, the first side wall part 46A has a first stepped part 52 and a second stepped part 54 which is formed under an upper surface 52 a of the first stepped part 52. The second stepped part 54 is formed at the entrance side opening part 50 of the first side wall part 46A. The upper surface 52 a of the first stepped part 52 or an upper surface 54 a of the second stepped part 54 are formed above the outer peripheral end part 24 b of the waste receiving surface 24. Each of the first stepped part 52 and the second stepped part 54 is formed under the upper surface part 20 of the toilet body 12.

The upper surface 52 a of the first stepped part 52 is in contact with a side end part of the first upper wall part 42A of the first upper surface side portion 38A to support the first upper wall part 42A. The upper surface 54 a of the second stepped part 54 is in contact with both side parts of the first hanging side wall part 44A of the first upper surface side portion 38A to support the first hanging side wall part 44A.

The second stepped part 54 has a side surface 54 b standing up from the upper surface 54 a of the second stepped part 54. The second stepped part 54 is formed so as to be horizontally recessed from the inner side surface of the first water passage 32A or the inner peripheral surface of the hanging wall part 34. Both side portions of the first hanging side wall part 44A are in contact with the side surface 54 b of the second stepped part 54.

The effects of the flush toilet 10 described above will be described. When not in contact with the toilet bowl side portion 40, the first hanging side wall part 44A of the first upper surface side portion 38A is in a state of hanging from the first upper wall part 42A. Therefore, the first hanging side wall part 44A of the first upper surface side portion 38A is applied with a downward force component by its own weight when being in the unfired state, and therefore is likely to extend downward.

In this respect, according to the present embodiment, the toilet bowl side portion 40 is in contact with the first hanging side wall part 44A of the first upper surface side portion 38A to support the first hanging side wall part 44A. Therefore, the downward force component by the own weight applied to the first hanging side wall part 44A of the first upper surface side portion 38A can be transmitted to the toilet bowl side portion 40. As a result, when the first hanging side wall part 44A of the first upper surface side portion 38A is in the unfired state, the downward force component applied to the first hanging side wall part 44A of the first upper surface side portion 38A can be reduced, and the first hanging side wall part 44A can be prevented from extending. As a result, it is easy to obtain the first water discharge hole 30A of the targeted shape with high precision by the first hanging side wall part 44A of the first upper surface side portion 38A.

In addition, the first hanging side wall part 44A of the first upper surface side portion 38A is in contact with the side surface 54 b of the second stepped part 54. Therefore, when the first upper surface side portion 38A is joined to the toilet bowl side portion 40, it is possible to regulate a relative movement of the first upper surface side portion 38A with respect to the toilet bowl side portion 40 in the horizontal direction by the contact between the first hanging side wall part 44A of the first upper surface side portion 38A and the side surface 54 b of the second stepped part 54. Accordingly, it is easy to perform an operation of positioning the first upper surface side portion 38A with respect to the toilet bowl side portion 40.

In addition to this, it is possible to regulate the relative movement of the first upper surface side portion 38A with the toilet bowl side portion 40 in the horizontal direction even by the contact between the first upper wall part 42A of the first upper surface side portion 38A and the side surface 52 b (see FIGS. 7 and 8) of the first stepped part 52.

As a method of manufacturing a toilet body 12, there is a method for constituting the toilet body 12 by a single cast molded product obtained by cast molding and forming water discharge holes 30A and 30B by cutting a portion of the cast molded product. In the case of adopting such a method, there is a problem that burrs are generated due to the cutting of a portion of the cast molded product and the water discharge holes 30A and 30B having the targeted shape cannot be formed with high precision.

In this respect, as in the present embodiment, when the toilet body 12 is structured by the upper surface side portions 38A and 38B and the toilet bowl side portion 40, the water discharge holes 30A and 30B can be formed by the upper surface side portions 38A and 38B and the toilet bowl side portion 40. Therefore, as compared with the method for forming water discharge holes 30A and 30B by the cutting of a portion of the cast molded product, there is an advantage that the water discharge holes 30A and 30B having the targeted shape can be formed with high precision. In addition to this, it is possible to more easily reduce the heights of the water passages 32A and 32B of the toilet body 12 as compared with the case where the toilet body 12 is constituted by the single cast molded product. As a result, there is an advantage that a water amount to be supplied into the water passages 32A and 32B through which flush water is discharged from the water discharge holes 30A and 30B can be reduced.

Although the first upper surface side portion 38A has been described in detail so far, the second upper surface side portion 38B is common in many respects. That is, the second upper surface side portion 38B has a second upper wall part 42B constituting the inner upper surface of the second water passage 32B and a second hanging side wall part 44B at least constituting the second hole forming part 36B of the hanging wall part 34.

The toilet bowl side portion 40 has a pair of second side wall parts 46B constituting the inner side surface 32 c of the second water passage 32B and a second lower wall part 48B constituting the inner lower surface 32 a of the second water passage 32B. Similarly to the first side wall part 46A, the second side wall part 46B also has a first stepped part 52 and a second stepped part 54. Although not shown, an upper surface of the first stepped part 52 is in contact with the second hanging side wall part 44B of the second upper surface side portion 38B to support the second hanging side wall part 44B. Although not shown, an upper surface of the second stepped part 54 is in contact with the second hanging side wall part 44B of the second upper surface side portion 38B to support the second hanging side wall part 44B.

Next, a second point of the flush toilet 10 will be described. Refer to FIGS. 2 and 3. The toilet body 12 includes a toilet drain channel 56 connected to a bottom part of the toilet bowl part 18 in addition to the toilet bowl part 18. The toilet drain channel 56 is a passage through which waste or water is discharged from an inside of the toilet bowl part 18 to a sewage water passage (not shown).

The water reservoir part 26 forms the bottom part of the toilet bowl part 18 and has a bottomed shape. The water reservoir part 26 has a bottom wall surface 26 a and a plurality of upright wall surfaces 26 b to 26 d standing up from the bottom wall surface 26 a. An inlet 56 a of the toilet drain channel 56 is opened at a rear part of the bottom wall surface 26 a. The water reservoir part 26 stores reservoir water.

The upright wall surfaces 26 b to 26 d are provided with a left upright wall surface 26 b (first upright wall surface) provided on a left side (right side on a page in FIG. 2) which is one of left and right sides of the water reservoir part 26 and a right upright wall surface 26 c (second upright wall part) provided on a right side (left side on a page in FIG. 2) which is the other of the left and right sides of the water reservoir part 26. In addition, the upright wall surfaces 26 b to 26 d are provided with a rear upright wall surface 26 d which is provided on the rear side of the water reservoir part 26. The left upright wall surface 26 b and the right upright wall surface 26 c have a shape to be tapered as it goes forward in order to form an induction flow Fwf (see FIG. 15) to be described later, and a front end part thereof is smoothly connected to each other through a first concavely curved surface 26 e. The left upright wall surface 26 b according to the present embodiment is smoothly connected to the rear upright wall surface 26 d via a second concavely curved surface 26 f The right upright wall surface 26 c according to the present embodiment is smoothly connected to the rear upright wall surface 26 d via a third concavely curved surface 26 g.

FIG. 10 is another plan view of the toilet body 12. In plan view, the waste receiving surface 24 includes a rear region 60 which overlaps the water reservoir part 26 in the front-rear direction X and is provided behind the water reservoir part 26 and a pair of lateral regions 62A and 62B which overlap the water reservoir part 26 and the rear region 60 in the left-right direction Y. In addition, in plan view, the waste receiving surface 24 has a front region 64 which overlaps the water reservoir part 26 or the lateral regions 62A and 62B in the front-rear direction X and is provided in front of the water reservoir part 26.

FIG. 11 is still another plan view of the toilet body 12. The toilet bowl part 18 has a shelf surface 66 for guiding flush water discharged from the water discharge holes 30A and 30B so as to swirl along the inner peripheral surface of the toilet bowl part 18. The shelf surface 66 according to the present embodiment is formed to be continued to the inner lower surface of the first water discharge hole 30A, and is formed to be continued to the inner lower surface of the second water discharge hole 30B.

FIG. 12 is an enlarged view of a portion of FIG. 3. FIG. 13 is a diagram mainly showing a portion of a cross section taken along the line B-B in FIG. 2. As shown in FIGS. 11 to 13, the shelf surface 66 is constituted by a part of a range extending radially inward from the outer peripheral end part 24 b of the waste receiving surface 24. The shape of the shelf surface 66 on a cut surface along the radial direction of the toilet bowl part 18 is a flat surface. In FIGS. 12 and 13, the shape of the cut surface along such a radial direction is shown.

The shelf surface 66 is formed so as to be continued from the rear region 60 of the waste receiving surface 24 to the lateral regions 62A and 62B. The shelf surface 66 according to the present embodiment is formed so as to be continued from the rear region 60 of the waste receiving surface 24 to each of the pair of lateral regions 62A and 62B. The shelf surface 66 according to the present embodiment is formed so as to be protruded from the lateral regions 62A and 62B of the waste receiving surface 24 to the front region 64. The shelf surface 66 according to the present embodiment is formed over the entire range in the left-right direction Y in the rear region 60 of the waste receiving surface 24.

In the plan view, the shelf surface 66 according to the present embodiment is not formed in front of the water reservoir part 26 at a position overlapping the water reservoir part 26 in the front-rear direction X. In the front region 64 of the waste receiving surface 24, a concavely curved surface part 68 which is recessed downward is provided in front of the water reservoir part 26 at the position overlapping the water reservoir part 26 in the front-rear direction X. Thereby, the waste receiving surface 24 is, as described later, structured so as to form a first divided flow Fwb (see FIG. 15) as a water flow introduced from the front, which is introduced from the waste receiving surface 24 into the water reservoir part 26.

The toilet bowl part 18 has a connecting surface 70 that connects between the shelf surface 66 and the upright wall surfaces 26 b to 26 d of the water reservoir part 26. The connecting surface 70 is a portion having a singular radius of curvature and a convexly curved surface shape which is continued to an inner peripheral end 66 a of the shelf surface 66 on a surface cut along the radial direction of the toilet bowl part 18. The connecting surface 70 continued to the shelf surface 66 is provided at least in the rear region 60 of the waste receiving surface 24. The connecting surface 70 according to the present embodiment is provided so as to be continued from the rear region 60 of the waste receiving surface 24 to the lateral regions 62A and 62B. This means the connecting surface 70 is also provided in the lateral regions 62A and 62B of the waste receiving surface 24. The connecting surface 70 according to the present embodiment is formed over the entire range in the left-right direction Y in the rear region 60 of the waste receiving surface 24.

The cleaning method by the flush toilet 10 described above will be described. The flush toilet 10 according to the present embodiment discharges waste by a flush-type washing method for flushing out the waste using a head of water. When a predetermined washing start condition is satisfied, the flush water supply device 14 performs a supply operation of supplying a predetermined amount of flush water to the water passages 32A and 32B. For example, the washing start condition is that the flush water supply device 14 receives a washing start instruction through an operation on an operation member such as a lever or electric devices such as a remote controller or a smart phone.

FIG. 14 is a diagram showing flows of flush water in a first stage. Here, the first stage refers to a stage in which the flush water starts to flow into the toilet bowl part 18. In FIG. 14, the flows of the flush water are indicated by an arrow.

The flush water is supplied from the flush water supply device 14 to each of the water discharge holes 30A and 30B through the water passages 32A and 32B, and discharged from each of the water discharge holes 30A and 30B. The first water discharge part 28A forms, by the flush water discharged from the first water discharge hole 30A, a first swirling flow Fwa which is directed forward of the waste receiving surface 24 in the right side portion 18 c of the toilet bowl part 18 and is directed backward of the waste receiving surface 24 in the left side portion 18 b of the toilet bowl part 18 via the front end part 24 a of the waste receiving surface 24. When traveling through the right lateral region 62B or the left lateral region 62A of the waste receiving surface 24, the first swirling flow Fwa is formed so as to pass through the shelf surface 66. The first swirling flow Fwa is formed as a main flow. In the present specification, the “main flow” refers to a streak-like flow which flows in a state where a portion of the flush water is partially gathered.

A portion of the flush water forming the first swirling flow Fwa is divided into a first divided flow Fwb at the front of the waste receiving surface 24 in the left side portion 18 b of the toilet bowl part 18. The first divided flow Fwb is formed as a main flow which flows down from the waste receiving surface 24 toward the water reservoir part 26.

A part Fwc of the first swirling flow Fwa which is directed backward of the waste receiving surface 24 without being divided into the first divided flow Fwb in the left side portion 18 b of the toilet bowl part 18 has a flow rate more than that of the first divided flow Fwb.

The second water discharge part 28B forms a first water flow Fwd which is introduced from the rear into the water reservoir part 26 and a second water flow Fwe which travels in a counterclockwise direction along the waste receiving surface 24 behind the first water flow Fwd, by discharging flush water from the second water discharge hole 30B in a wide angle range. The first water flow Fwd and the second water flow Fwe are formed as the main flow. The flow rate of the first water flow Fwd is more than the flow rate of the second water flow Fwe. When the first water flow Fwd does not merge with the part Fwc of the first swirling flow Fwa, the first water flow Fwd is introduced from the rear into the water reservoir part 26 in the left side portion 18 b of the toilet bowl part 18. At this time, the first water flow Fwd is formed to have a flow rate introduced from the rear of the water reservoir part 26 in the left side portion 18 b of the toilet bowl part 18 more than the flow rate flowing from the rear of the water reservoir part 26 in the right side portion 18 c of the toilet bowl part 18. At this time, the flow rate of the first water flow Fwd introduced from the rear of the water reservoir part 26 in the right side portion 18 c of the toilet bowl part 18 may be zero.

FIG. 15 is a diagram showing flows of flush water in a second stage. Here, the second stage means a stage after time elapses from the first stage. The flows of the first swirling flow Fwa and the first divided flow Fwb are the same as in the first stage.

In the second stage, the first water flow Fwd and the second water flow Fwe formed by the flush water discharged from the second water discharge holes 30B merge with the part Fwc of the first swirling flow Fwa. As a result, the first water flow Fwd or the second water flow Fwe is formed to pass through a location closer to the outer peripheral end part 24 b of the waste receiving surface 24 at the rear region 60 of the waste receiving surface 24 than the position where the first water flow Fwd or the second water flow Fwe flows prior to merging with the part Fwc of the first swirling flow Fwa.

At this time, both the first water flow Fwd or the second water flow Fwe is formed to travel in the counterclockwise direction along the rear region 60 of the waste receiving surface 24. It can be said that the first water discharge part 28A or the second water discharge part 28B forms the first water flow Fwd traveling in a counterclockwise direction along the rear region 60 of the waste receiving surface 24 by discharging the flush water from the first water discharge hole 30A or the second water discharge hole 30B. The first water flow Fwd is formed to travel in a counterclockwise direction along the shelf surface 66 or the connecting surface 70 in the rear region 60 of the waste receiving surface 24.

When merging with the part Fwc of the first swirling flow Fwa, the first water flow Fwd is introduced into the rear which is the water reservoir part 26 in the right side portion 18 c of the toilet bowl part 18 so as to fall down while being in contact with mainly the right upright wall surface 26 c of the water reservoir part 26. At this time, the first water flow Fwd is formed to have a flow rate introduced from the rear into the water reservoir part 26 in the right side portion 18 c of the toilet bowl part 18 more than the flow rate introduced from the rear into the water reservoir part 26 in the left side portion 18 b of the toilet bowl part 18. At this time, the flow rate of the first water flow Fwd introduced from the rear of the water reservoir part 26 in the left side portion 18 b of the toilet bowl part 18 may be zero. The first water flow Fwd is the main flow having the largest flow rate among the water flows which is introduced from the waste receiving surface 24 into the water reservoir part 26.

FIG. 16 is another diagram showing the flows of flush water in the second stage. As shown in FIGS. 15 and 16, the first water flow Fwd which is introduced from the rear into the water reservoir part 26 flows downward while being in contact with the right upright wall surface 26 c of the water reservoir part 26. After the direction of the first water flow Fwd is changed to an upper side and a rear side by colliding with the bottom wall surface 26 a and the left upright wall surface 26 b of the water reservoir part 26, the first water flow Fwd rises in the water reservoir part 26 to form the induction flow Fwf which becomes a vertical swirling flow falling by its own weight. The induction flow Fwf rises backward in the water reservoir part 26 and then falls, and thus becomes a flow which pushes waste into the inlet 56 a of the toilet drain channel 56. The water reservoir part 26 is structured so as to form the induction flow Fwf which pushes waste into the toilet drain channel 56 by being introduced from the rear into the water reservoir part 26 while being in contact with the right upright wall surface 26 c.

The first divided flow Fwb introduced from the front into the above-described water reservoir part 26 merges with the induction flow Fwf. Thereby, a force of water of the induction flow Fwf is amplified.

The second water flow Fwe travels in the counterclockwise direction along the rear region 60 of the waste receiving surface 24 and travels forward along the right lateral region 62B of the waste receiving surface 24. The second water flow Fwe merges with the first swirling flow Fwa in the right lateral region 62B of the waste receiving surface 24, and amplifies the force of water of the first swirling flow Fwa.

As described above, the first water flow Fwd merges with the part Fwc of the first swirling flow Fwa, and then is formed to be introduced from the rear into the water reservoir part 26 while being in contact with the right upright wall surface 26 c of the water reservoir part 26. As a result, as compared with the case where not merging with the part Fwc of the first swirling flow Fwa, the flow rate of the first water flow Fwd introduced from the rear of the water reservoir part 26 can be increased and the waste discharge capability can be improved.

In particular, even when not merging with the part Fwc of the first swirling flow Fwa, the first water flow Fwd is formed so as to be introduced from the rear into the water reservoir part 26. Therefore, when the first swirling flow Fwa merges with the first water flow Fwd, the flows of the first swirling flow Fwa is easily changed to be directed to the water reservoir part 26. Accordingly, a ratio of the water flow traveling along the rear region 60 of the waste receiving surface 24 without being introduced from the rear into the water reservoir part 26 to a total flow rate of the first swirling flow Fwa is reduced, and a ratio of the water flow introduced from the rear into the water reservoir part 26 to the total flow rate of the first swirling flow Fwa can be increased as much. As a result, the flow rate of the first water flow Fwd introduced from the rear of the water reservoir part 26 can be increased, and the waste discharge capability can be further improved.

Here, in the flush toilet 10 according to the present embodiment, the following measures are taken in order to increase the flow rate of the first water flow Fwd introduced from the rear to the water reservoir part 26 as described above. FIG. 17 is a graph showing the slope of the shelf surface 66 in the radial direction. Here, the “radial slope” means the slope of the shelf surface 66 at the surface cut along the radial direction of the toilet bowl part 18 (hereinafter, also simply referred to as a slope). Positions A to C in FIG. 17 correspond to positions A to C in FIG. 11, respectively.

As shown in FIGS. 11 to 13 and 17, the slope of the shelf surface 66 in the rear region 60 described above is set to be larger than the slope of the shelf surface 66 in the lateral regions 62A and 62B. In plan view, the slope of the shelf surface 66 according to the present embodiment is set to be largest at a position A overlapping the left-right center line Lc of the toilet bowl part 18. The slope of the shelf surface 66 is set to be continuously smaller as the shelf surface 66 is separated from the position A overlapping the left-right center line Lc in the circumferential direction. The slope of the shelf surface 66 in the lateral regions 62A and 62B is also considered to be set to be continuously smaller as the shelf surface 66 is separated from the rear region 60 in the circumferential direction.

Thereby, as compared with the case where the slope of the shelf surface 66 in the rear region 60 is equal to or less than the slope of the shelf surface 66 in the lateral regions 62A and 62B, a portion of the flush water traveling in the counterclockwise direction along the shelf surface 66 in the rear region 60 appropriately and easily drops into the water reservoir part 26. As a result, the amount of flush water introduced from the rear of the water reservoir part 26 can be increased, and the waste discharge capability can be improved.

In addition, since the flush water can be guided along the inner peripheral surface of the toilet bowl part 18 by the shelf surface 66 of the rear region 60, an appropriate amount of flush water can also travel into the waste receiving surface 24 of the right lateral region 62B continued to the rear region 60 in the counterclockwise direction. Therefore, it is possible to improve the washing ability of the waste receiving surface 24 in the right lateral region 62B while increasing the amount of flush water introduced from the rear into the water reservoir part 26.

FIG. 18 is a graph showing the radius of curvature of the connecting surface 70 in the radial direction. Here, the “radius of curvature in the radial direction” means the radius of curvature at the surface cut along the radial direction of the toilet bowl part 18 (hereinafter, also simply referred to as a radius of curvature). Positions A to E in FIG. 18 correspond to positions A to E in FIG. 11, respectively.

As shown in FIGS. 11 to 13 and 18, the radius of curvature of the connecting surface 70 in the rear region 60 described above is set to be larger than the radius of curvature of the connecting surface 70 in the lateral regions 62A and 62B. In plan view, the radius of curvature of the connecting surface 70 according to the present embodiment is set to be largest at the position A overlapping the left-right center line Lc of the toilet bowl part 18 in the rear of the water reservoir part 26. The radius of curvature of the connecting surface 70 is set to be continuously smaller as the connecting surface 70 is separated from the position A overlapping the left-right center line Lc in the circumferential direction. The radius of curvature of the connecting surface 70 in the lateral regions 62A and 62B is also considered to be set to be continuously smaller as the connecting surface 70 is separated from the rear region 60 in the circumferential direction.

As a result, as compared with the case where the radius of curvature of the connecting surface 70 in the rear region 60 is equal to or less than the radius of curvature of the connecting surface 70 in the lateral regions 62A and 62B, the range in the radial direction where the connecting surface 70 having a convexly curved surface shape is formed can be widened. Accordingly, the amount of flush water passing over the connecting surface 70 in the rear region 60 can be increased, and it becomes easy to increase the amount of flush water to flow down from the connecting surface 70 into the water reservoir part 26. As a result, the amount of flush water introduced from the rear into the water reservoir part 26 can be further increased, and the waste discharge capability can be improved.

In order to increase the amount of flush water introduced from the rear into the water reservoir part 26, a method for guiding the flush water to the water reservoir part 26 by the concavely curved surface which is provided in a wide range of the rear region 60 of the waste receiving surface 24 can be considered. In this respect, according to the present embodiment, the rear region 60 of the waste receiving surface 24 is provided with the shelf surface 66 which is a flat surface and the connecting surface 70 which has the convexly curved surface shape, and the amount of flush water introduced from the rear into the water reservoir part 26 by at least the slope of the shelf surface 66 can be increased. Therefore, in order to increase the amount of flush water introduced from the rear into the water reservoir part 26, it is not necessary to provide the concavely curved surface in the wide range of the rear region 60 of the waste receiving surface 24. As a result, the rear region 60 of the waste receiving surface 24 is wiped without being hindered, and good cleaning performance can be obtained.

In plan view, the connecting surface 70 is provided so as to extend along the entire circumference of the water reservoir part 26. There are locations where the connecting surface 70 is not connected to the inner peripheral end 66 a of the shelf surface 66 except for the rear region 60. In plan view, the radius of curvature of the connecting surface 70 is set to be smallest at the position E overlapping the left-right center line Lc of the toilet bowl part 18 in the front of the water reservoir part 26.

Next, other features of the flush toilet 10 will be described. FIG. 19 is an enlarged view of a portion of FIG. 4. The toilet bowl part 18 has a surface portion 18 d which constitutes the inner peripheral surface of the toilet bowl part 18, and is continued to an inner side surface 30 c of the first water discharge hole 30A and extends in a discharge direction Pa along the central axis line Ld of the first water discharge hole 30A. The surface portion 18 d according to the present embodiment includes the above-described hanging wall part 34.

A line obtained by extending the central axis line Ld of the first water discharge hole 30A in the discharge direction Pa in plan view is referred to as an extension line Le. In the present embodiment, the extension line Le is provided so as to pass through a location avoiding the water reservoir part 26 in plan view.

In plan view, the surface portion 18 d of the toilet bowl part 18 extends toward an opposite side (left side of a page in FIG. 19) to the water reservoir part 26 across the above-described extension line Le as it goes from the inner side surface 30 c of the first water discharge hole 30A to the discharge direction Pa. In plan view, such a surface portion 18 d forms a corner 30 d having an obtuse angle between the surface portion 18 d and the inner side surface 30 c of the first water discharge hole 30A. The surface portion 18 d is curved so as to be separated from the above-described extension line Le on the opposite side to the water reservoir part 26 and approach the extension line Le as it goes toward the discharge direction Pa.

As a result, the flush water discharged from the first water discharge hole 30A becomes difficult to flow along the surface portion 18 d of the toilet bowl part 18 immediately after being discharged from the first water discharge hole 30A, and the flow rate of water flowing along the surface portion 18 d can be suppressed. Advantages thereof will be described.

It is considered that the case where the flush water discharged from the first water discharge hole 30A merges with the second water flow Fwe from the water reservoir part 26 side with respect to the above-described extension line Le in plan view. At this time, the flush water discharged from the first water discharge hole 30A is applied with a force component Fa approaching the surface portion 18 d of the toilet bowl part 18 by merging with the second water flow Fwe. In this case, according to the present embodiment, the flow rate of water flowing along the surface portion 18 d of the toilet bowl part 18 can be suppressed. Therefore, even if the force component Fa approaching the surface portion 18 d of the toilet bowl part 18 is applied, the situation where a large amount of flush water discharged from the first water discharge hole 30A forcibly collides with the surface portion 18 d of the toilet bowl part 18 can be avoided and the occurrence of splash can be suppressed.

FIG. 20A is a cross-sectional view taken along the line F-F in FIG. 3, FIG. 20B is a cross-sectional view taken along the line G-G in FIG. 3, and FIG. 20C is a cross-sectional view taken along the line H-H in FIG. 3.

As described above, the present invention has been described above with respect to the present embodiment. Next, modifications of each component will be described.

The toilet body 12 has been described as an example of a floor-mounted type, but may be wall-mounted type. The flush toilet 10 may be washed using another washing method other than the wash-off type. The washing method is, for example, a siphon method. The flush water supply device 14 is not particularly limited for the specific example. The flush water supply device 14 may also be structured using, for example, a flush valve or the like.

Regarding First Point

The height Ha of the hole forming parts 36A and 36B of the hanging wall part 34 may be set to a size less than half of the height Hb described above.

The toilet body 12 may be constituted by a single cast molded product without joining the upper surface side portions 38A and 38B to the toilet bowl side portion 40.

The hanging side wall parts 44A and 44B of the upper surface side portions 38A and 38B may be supported by being in contact with a location different from the second stepped part 54 of the toilet bowl side portion 40. For example, the hanging side wall parts 44A and 44B may be supported by being in contact with a location connected to the outer peripheral end part 24 b of the waste receiving surface 24 of the toilet bowl side portion 40. The hanging side wall parts 44A and 44B of the upper surface side portions 38A and 38B may be not to be in contact with the side surface 54 b of the second stepped part 54 of the toilet bowl side portion 40.

Regarding Second Point

The toilet body 12 may have only the first water discharge part 28A and may not have the second water discharge part 28B. In this case, the first water discharge part 28A may form a water flow traveling in a circumferential direction along the rear region 60 of the waste receiving surface 24 by the flush water discharged from the first water discharge hole 30A. This water flow is, for example, the above-described first water flow Fwd. In this case, the position of the first water discharge hole 30A of the first water discharge part 28A is not particularly limited. For example, the first water discharge hole 30A may be formed at a position where the second water discharge hole 30B is present in the embodiment.

The first water discharge hole 30A, the second water discharge hole 30B, the first swirling flow Fwa, the first divided flow Fwb, the first water flow Fwd, the second water flow Fwe, the induction flow Fwf, and the like may be provided at an opposite position on the left and right with respect to the position in the embodiment. For example, the first water discharge part 28A may discharge the flush water in a clockwise direction into the toilet bowl part 18 from the first water discharge hole 30A to form the first water flow Fwd traveling in a clockwise direction along the rear region 60 of the waste receiving surface 24. In this case, the water reservoir part 26 may be structured to form the induction flow Fwf by the water flow introduced from the rear into the water reservoir part 26 while being in contact with the left upright wall surface 26 b on the left and right sides of the water reservoir part 26.

The shelf surface 66 of the waste receiving surface 24 may be formed so as to be continued from the rear region 60 of the waste receiving surface 24 to any one of the lateral regions 62A and 62B.

The example in which the slope of the shelf surface 66 in the rear region 60 of the waste receiving surface 24 is set to continuously change in the circumferential direction of the toilet bowl part 18 was described. In addition to this, the slope of the shelf surface 66 in the rear region 60 may be changed stepwise in the circumferential direction of the toilet bowl part 18 or may be set constant in the circumferential direction in the rear region 60. In any case, the slope of the shelf surface 66 in the rear region 60 may be set to be larger than the slope of the shelf surface 66 in the lateral regions 62A and 62B. In addition, the slope of the shelf surface 66 in the rear region 60 may be set to be larger than the slope of the shelf surface 66 in any one of the pair of lateral regions 62A and 62B.

The connecting surface 70 of the rear region 60 of the waste receiving surface 24 may have a concavely curved surface shape.

The example in which the radius of curvature of the connecting surface 70 in the rear region 60 of the waste receiving surface 24 is set to continuously change in the circumferential direction of the toilet bowl part 18 was described. In addition to this, the radius of curvature of the connecting surface 70 in the rear region 60 may be changed stepwise in the circumferential direction of the toilet bowl part 18 or may be set constant in the circumferential direction in the rear region 60. In any case, the radius of curvature of the connecting surface 70 in the rear region 60 may be set to be larger than the radius of curvature in the lateral regions 62A and 62B. In addition, the radius of curvature of the connecting surface 70 in the rear region 60 may be set to be larger than the radius of curvature of the connecting surface 70 in any one of the pair of lateral regions 62A and 62B.

The embodiments and the modifications of the present invention have been described in detail above. The above-described embodiments and modifications describe merely specific examples for implementing the present invention. The contents of the embodiments and modifications do not limit the technical scope of the present invention, and many changes in design such as changes, additions, deletions and the like of constituent elements can be made without departing from the concept of the invention defined in the claims. In the above-described embodiments, although the description of “of the embodiment”, “in the embodiment” and the like regarding the contents which can be changed in design as described above is emphasized, even the contents without such description can be changed in design. Any combination of the above components is also effective as an aspect of the present invention. The hatching attached to the cross section of the drawing does not limit the material of the hatched object.

When the inventions embodied by the embodiments and modifications set forth above are generalized, the following technical ideas are derived. In the following, description will be made using the aspect described in SUMMARY OF THE INVENTION.

In a toilet body according to a second aspect, in the first aspect, the waste receiving surface has the connecting surface having the convexly curved surface shape which is connected to an upright wall surface of the water reservoir part and the shelf surface and is continued to the shelf surface, and the connecting surface may be provided at least in the rear region of the waste receiving surface. According to this aspect, in order to increase the amount of flush water introduced from the rear into the water reservoir part, it is not necessary to provide the concavely curved surface in the wide range of the rear region of the waste receiving surface. As a result, the rear region of the waste receiving surface is easily wiped without being hindered, and good cleaning performance can be obtained.

In a toilet body according to a third aspect, in the second aspect, the connecting surface is also provided in the lateral region of the waste receiving surface, and the radius of curvature of the connecting surface in the rear region in the radial direction may be set to be larger than the radius of curvature in the radial direction of the connecting surface in the lateral region. According to this aspect, the range in the radial direction in which the connecting surface having the convexly curved surface shape is formed can be wider than the case where the radius of curvature of the connecting surface in the rear region is made equal to or less than the radius of curvature of the connecting surface in the lateral region. As a result, the amount of flush water passing over the connecting surface in the rear region can be increased, and it becomes easy to increase the amount of flush water to flow down from the connecting surface into the water reservoir part. As a result, the amount of flush water introduced from the rear of the water reservoir part can be further increased, and the waste discharge capability can be improved.

In the toilet body according to a fourth aspect, in any one of the first to third aspects, wherein the first water discharge part discharges flush water from the first water discharge hole to form a first swirling flow which travels backward along a first side portion of one of left and right sides of the toilet bowl part, and the toilet body further comprises a second water discharge part which has a second water discharge hole which is formed in the first side portion behind the water reservoir part and discharges the flush water from the second water discharge hole toward one side in the circumferential direction into the toilet bowl part to form a first water flow introduced from the rear into the water reservoir part, and wherein the first water flow may merge with a portion of the first swirling flow and then be formed to be introduced from the rear into the water reservoir part while being in contact with the upright wall surface. According to this aspect, it is possible to increase the flow rate of the water flow introduced from the rear into the water reservoir part, and to improve the waste discharge capability.

A toilet body according to a fifth aspect includes a toilet bowl part which has a bowl-shaped waste receiving surface and a water reservoir part recessed downward from a lower end edge of the waste receiving surface, a toilet drain channel which is connected to a bottom part of the toilet bowl part, a first water discharge part which discharges flush water from a first water discharge hole toward one side in a circumferential direction into the toilet bowl part to form a first swirling flow traveling backward along a first side portion of one of left and right sides of the toilet bowl part, and a second water discharge part which has a second water discharge hole formed at the first side portion behind the water reservoir part and discharges the flush water from the second water discharge hole toward one side in the circumferential direction into the toilet bowl part to form a first water flow introduced from the rear into the water reservoir part, in which the water reservoir part is structured to form an induction flow which pushes waste into the toilet drain channel by the water flow introduced from the rear into the water reservoir part while being in contact with an upright wall surface provided on one side out of left and right sides of the water reservoir part, and the first water flow merges with a portion of the first swirling flow and then is formed to be introduced from the rear into the water reservoir part while being in contact with the upright wall surface. According to this aspect, it is possible to increase the flow rate of the water flow introduced from the rear into the water reservoir part, and to improve the waste discharge capability.

In a toilet body according to a sixth aspect, in any one of the first to fifth aspects, the toilet bowl part has a surface portion which constitutes an inner peripheral surface of the toilet bowl part and extends in a discharge direction along a central axis line of the first water discharge hole from an inner side surface of the first water discharge hole, and the surface portion may be formed to extend toward an opposite side to the water reservoir part across an extension line of the central axis line in plan view as it goes toward the discharge direction from the inner side surface of the first water discharge hole. A case is considered in which the flush water discharged from the first water discharge hole is applied with the force component approaching the surface portion of the toilet bowl part by merging with another water flow. In this case, according to this aspect, the situation where a large amount of flush water discharged from the first water discharge hole forcibly collides with the surface portion of the toilet bowl part can be avoided and the occurrence of splash can be suppressed.

By generalizing the invention embodied by the above-described embodiment and modifications, the invention described in the following items can be derived.

First Item

A toilet body includes a toilet bowl part and a first water discharge part which discharges flush water from a first water discharge hole toward one side in a circumferential direction into the toilet bowl part, in which the toilet bowl part has a surface portion which constitutes an inner peripheral surface of the toilet bowl part and extends in a discharge direction along a central axis line of the first water discharge hole from an inner side surface of the first water discharge hole, and the surface portion is formed to extend toward an opposite side to the water reservoir part across the central axis line in plan view as it goes toward the discharge direction from the inner side surface of the first water discharge hole.

Second Item

A first aspect of the invention of a second item is a toilet body. The toilet body includes a toilet bowl part, a water discharge hole for discharging flush water into the toilet bowl part, and a water passage which supplies the flush water to the water discharge hole, in which the toilet bowl part has a hanging wall part which hangs from an upper end inner edge part of the toilet bowl part and has the water discharge hole penetrating therethrough, and an inner lower surface of the water discharge hole is smoothly connected to an inner lower surface of the water passage and an inner surface of the toilet bowl part.

The problems of the first aspect of the invention of the second item are as follows.

JP 2015-194005 A discloses a toilet body which includes a toilet bowl part, a water discharge hole for discharging flush water into the toilet bowl part, and a guide part which is a wall part forming the water discharge hole.

The water discharge hole of JP 2015-194005 A is formed at a recessed location on an outer side in the radial direction of the toilet bowl part with respect to the upper end inner edge part of the toilet bowl part. As a result, the guide part which is the wall part forming the water discharge hole is also disposed at a position recessed from the upper end inner edge part of the toilet bowl part. The inventors have found that there is room for improvement from the viewpoint of obtaining good cleaning performance as a result of examining the structure.

An aspect of the invention described in the second item is made in view of such a problem, and one of the objects of the present invention is to provide a technology capable of obtaining good cleaning performance for the toilet body.

In the toilet body according to the second aspect, in the first aspect, the hanging wall part has a hole forming part which forms the water discharge hole and is provided above the water discharge hole, and the height of the hole forming part may be set to be half or more of the height from the upper end of the upper end inner edge part to the inner lower surface of the water discharge hole.

In the toilet body according to the third aspect, in the first or second aspect, the toilet body is structured by joining an upper surface side portion with a toilet bowl side portion under the upper surface side portion, in which the upper surface side portion has an upper wall part constituting an inner upper surface of the water flow passage and a hanging side wall part at least constituting a portion of the hanging wall part provided above the water discharge hole, and the toilet bowl side portion may support the hanging side wall part by being in contact with the hanging side wall part.

In the toilet body according to the fourth aspect, in the third aspect, the toilet bowl side portion has a side wall part constituting an inner side surface of the water flow passage, and a stepped part formed on the side wall part, in which the upper surface of the stepped part may be in contact with the inner side wall part to support the side wall part.

In the toilet body according to the fifth aspect, in the third or fourth aspect, the stepped part has a side surface standing up from the upper surface of the first stepped part, and the side wall part may be in contact with the side surface of the first stepped part. 

1. A toilet body, comprising: a toilet bowl part which has a bowl-shaped waste receiving surface and a water reservoir part recessed downward from a lower end edge of the waste receiving surface; a toilet drain channel which is connected to a bottom part of the toilet bowl part; and a first water discharge part which discharges flush water from a first water discharge hole toward one side in a circumferential direction into the toilet bowl part to form a water flow which travels along a rear region of the waste receiving surface located behind the water reservoir part toward one side in a circumferential direction, wherein the water reservoir part is structured to form an induction flow which pushes waste into the toilet drain channel by introducing a water flow from the rear of the toilet bowl part into the water reservoir part while contacting an upright wall surface provided on one side out of left and right sides of the water reservoir part, the waste receiving surface has a shelf surface for guiding flush water discharged from the water discharge hole toward one side in the circumferential direction, the shelf surface is structured so that a shape in a surface cut along a radial direction of the toilet bowl part is a flat surface, and a slope in the radial direction of the shelf surface in the rear region is set to be larger than a slope in the radial direction of the shelf surface in a lateral region of the waste receiving surface located on either the left or right side of the water reservoir part.
 2. The toilet body according to claim 1, wherein the waste receiving surface has a connecting surface having a convexly curved surface shape which is connected to an upright wall surface of the water reservoir part and the shelf surface and is continued to the shelf surface, and the connecting surface is provided at least in the rear region of the waste receiving surface.
 3. The toilet body according to claim 2, wherein the connecting surface is also provided in the lateral region of the waste receiving surface, and a radius of curvature in a radial direction of the connecting surface in the rear region is set to be larger than a radius of curvature in a radial direction of the connecting surface in the lateral region.
 4. The toilet body according to claim 1, wherein the first water discharge part discharges flush water from the first water discharge hole to form a first swirling flow which travels backward along a first side portion of one of left and right sides of the toilet bowl part, the toilet body further comprising a second water discharge part which has a second water discharge hole which is formed in the first side portion behind the water reservoir part and discharges the flush water from the second water discharge hole toward one side in the circumferential direction into the toilet bowl part to form a first water flow introduced from the rear into the water reservoir part, and wherein the first water flow merges with a portion of the first swirling flow and then is formed to be introduced from the rear into the water reservoir part while being in contact with the upright wall surface.
 5. A toilet body, comprising: a toilet bowl part which has a bowl-shaped waste receiving surface and a water reservoir part recessed downward from a lower end edge of the waste receiving surface; a toilet drain channel which is connected to a bottom part of the toilet bowl part; a first water discharge part which discharges flush water from a first water discharge hole toward one side in a circumferential direction into the toilet bowl part to form a first swirling flow traveling backward along a first side portion of one of left and right sides of the toilet bowl part; and a second water discharge part which has a second water discharge hole formed at the first side portion behind the water reservoir part and discharges the flush water from the second water discharge hole toward one side in the circumferential direction into the toilet bowl part to form a first water flow introduced from the rear into the water reservoir part, wherein the water reservoir part is structured to form an induction flow which pushes waste into the toilet drain channel by water flow introduced from the rear into the water reservoir part while being in contact with an upright wall surface provided on one side out of left and right sides of the water reservoir part, and the first water flow merges with a portion of the first swirling flow and then is formed to be introduced from the rear into the water reservoir part while being in contact with the upright wall surface.
 6. The toilet body according to claim 1, wherein the toilet bowl part has a surface portion which constitutes an inner peripheral surface of the toilet bowl part and extends in a discharge direction along a central axis line of the first water discharge hole from an inner side surface of the first water discharge hole, and the surface portion is formed to extend toward an opposite side to the water reservoir part across an extension line of the central axis line in plan view as it goes toward the discharge direction from the inner side surface of the first water discharge hole.
 7. The toilet body according to claim 1, further comprising: a water passage which supplies the flush water to the first water discharge hole, wherein the toilet bowl part has a hanging wall part which hangs from an upper end inner edge part of the toilet bowl part and has the first water discharge hole penetrating therethrough, and an inner lower surface of the first water discharge hole is smoothly connected to an inner lower surface of the water passage and an inner surface of the toilet bowl part. 